Question / Help Question about OBS Studio and vMIx and RTMP Sources

[belboz]

Hello all,

Questions for vMIx users with OBS and people using RTMP streams in OBS.

I do a dual PC stream environment since I do some console stuff along with PC. My stream PC is an i7 4770K with a basic Geforce 560 TI in it. No games played on it obviously. Latest OBS Studio 18.0.1. Latest vMix also (19.0.0.46). Windows 10 Creators Update. 4GB Memory.

I have vMix set for NTSC 1080p 60fps. My rtmp sources I am adding through it are the same settings (people are streaming to my dedicated server running Linux/ngnix/rtmp module). The rtmp stream is 6Mb.

I have the external output in vmix set to 1080p 60fps NTSC.

When I add a video capture source to OBS and use the vMix source for it. I get the output of vMix in OBS. It looks good on static screens. Definitely 1080p. But movement looks blurry and looks like it is being re-encoded. Vmix says the external output is 1080p 60fps.

I am not using vMix to record, to stream or anything. For this test I was just using it to take a single 1080p 60fps rtmp stream and relay it to OBS. Eventually using multiple sources and picture in picture is the goal.

If I add the rtmp stream directly in OBS as a media source and skip vMix it looks great.

Does vMix re-encode everything it sends to the external output? Or is there something I am missing? Do I need to have my sources be a higher rez/bitrate then what OBS is streaming out to? Am I just missing something on how to use vMix. I have the 1080p version that supports four inputs.

I wanted to use vMix because it seems more stable with rtmp sources then the media source in OBS. Sometimes it seems OBS shows audio for the media source but doesn't output to the stream, even though you have audio output showing for the media source on the OBS mixer. I have had this problem with OBS media source video files too. My solution was to use browser source plugin and add embed the videos in an HTML file and add that in OBS.

I have also had issues with multiple 1080p 60fps rtmp sources in obs. Corrupting my audio on all obs sources. I suspect it is because of CPU usage. It seems like 1080p rtmp sources as media sources take a lot of CPU resources. Not sure if that is because OBS is not using my GPU for those resources (do have the hardware acceleration option selected for the media sources). Could it be compositing issues not happening on the older 560 ti GPU? Or it not supporting hardware acceleration in OBS?

Anyway any vMix and RTMP experts have any thoughts?

 

[Fenrir]

While I don't have much experience with vMix, that seems like a bit of overkill just to get the RTMP stream into OBS. Have you tried the VLC Source instead of Media Source? It should be much more stable than the current Media Source plugin. It simply needs VLC installed on your system to be active (it will check for active VLC installs when OBS is launched).

Also, just as a side note, the Media Source underwent significant changes for the 19.0.0 release, which should be coming soon to address issues like this.

 

[belboz]

vMix allows a lot of options for quickly switching to different picture in picture modes with multiple sources (in my future case multiple rtmp streams).

That flexibility is something I wanted to use. But the quality of the output was of concern for me. I know there are some on here who have talked about using vMix, so hopefully they can chime in.

I will try the VLC source though, thanks for the tip!